The burden of proof lies with the person making the POSITIVE Assertion (you), not the negative one (me).

Science 101: if a person comes along with a new claim, it is THEIR responsibility to prove THEIR claim - it is not everybody else's responsibility to defend the accepted one!

Now, if I am change the subject. . .

If you wish for us all to believe that ETs were involved in our past, then offer irrefutable proof. Don't give us obscure cave drawing or texts open to interpretation. Give us something concrete, like a mummified alien body or piece of technology.